It is often necessary, for consumer acceptance, improved shelf-life and/or regulatory compliance, to measure total content of a given moiety (e.g., sulfur) in a component or constituent employed in the production of a product and/or in the finished product, such as a processed comestible. Quantitative determination of total moiety content is typically achieved by catalytically converting all moiety-containing species in a sample into a single moiety-containing species and then measuring the concentration of that single species. For example, measurement of total sulfur content typically involves the conversion of various alternative sulfur-containing compounds potentially present in the sample gas (e.g., carbonyl sulfide (COS), methyl mercaptan (CH3SH), ethyl mercaptan (CH4CH3SH), dimethyl sulfide (CH3SCH3), carbon disulfide (CS2), 2-propanethiol (CH3SHC2H5), tert-butyl mercaptan ((CH3)3CSH), 1-propanethiol (CH3(CH2)2SH), thiophene (C4H4S), n-butanethiol (CH3(CH2)3SH), diethyl sulfide (CH3CH2SCH2CH3), methyl ethyl sulfide (CH3SCH2CH3), 2-methyl-1-propanethiol ((CH3)2CHCH2SH), 1-methyl-1-propanethiol (CH3CH2CHSHCH3), etc.) into hydrogen sulfide (H2S) at approximately 1,000° C. in the presence of hydrogen and a nickel catalyst, followed by measurement of hydrogen sulfide in the converted sample with a suitable measuring instrument such as a gas chromatograph, mass spectrometer or photo-ionization detector.
This technique, while generally useful, lacks the accuracy, precision and sensitivity required for many applications, due in major part to vagaries resulting from and introduced by the required catalytic conversion of the single moiety-containing species into the select moiety-containing species.
Hence, a substantial need continues to exist for a highly sensitive analytical instrument capable of accurately and precisely measuring total moiety content (e.g., sulfur) in a test gas when one or more alternative moiety-containing species needs to be catalytically converted into a select moiety-containing species for measurement. More specifically, a substantial need continues to exist for a reactor capable of quickly achieving absolute catalytic conversion of alternative moiety-containing species into a single select moiety-containing species for subsequent measurement, in the absence of any appreciable absorption, adsorption or outgassing of the moiety or a moiety-containing compound.